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GIFT  OF 


The  Climate  of  Duluth 

Minnesota 


BY 

H.  W.  RICHARDSON,  LOCAL  FORECASTER 

UNITED  STATES  WEATHER  BUREAU 

PREPARATION  AUTHORIZED   AND  DATA  APPROVED 
BY 

CHARLES  F.  MARVIN,  Chief  U.  S.  Weather  Bureau 


PUBLISHED  BY 

COMMERCIAL  CLUB  OF  DULUTH, 

DULUTH,  MINNESOTA. 


UNIVERSITY 

V   >      OF 


The  Service  of  the  Local 
United  States  Weather  Bureau 


The  value  of  the  Weather  Bureau  forecasts  and 
warnings  and  other  information  as  utilized  by  the  ex- 
tensive commercial  interests  at  the  Head  of  the  Lakes 
is  approximately  $2,000,000  annually,  a  net  return  of 
about  30,000  per  cent,  on  the  investment  or  cost  of  opera- 
tion of  the  Duluth  station.  Of  the  amount  mentioned 
practically  $1,000,000  is  annually  saved  the  shippers  and 
transportation  companies  handling  perishable  freight, 
about  $600,000  is  saved  the  marine  and  iron  ore  interests, 
while  at  least  $400,000  is  the  value  of  the  service  to  other 
lines  of  business.  These  figures,  while  perhaps  astound- 
ing, can  easily  be  verified.  The  forecasts  and  warnings 
are  correct  80  to  about  90  per  cent,  of  the  time,  and 

rarely  does  a  severe  storm  or  cold  wave  come  in  unan- 
nounced. It  more  often  happens  that  such  conditions 
may  not  materialize  to  the  extent  anticipated,  which 
source  of  error  is  really  on  the  safe  side  of  the  ledger. 
As  stated  elsewhere  it  is  the  exception  that  excites  com- 
ment. In  addition  to  the  interests  mentioned  the  fore- 
casts and  Weather  Bureau  data  are  more  or  less  effect- 
ively used  by  local  contractors  and  builders,  farmers, 
gardeners,  florists,  dairymen,  stoc'k  raisers,  department 
stores,  heating  companies,  managers  of  office  buildings, 


289048 


4  THE  SERVICE  OF  LOCAL  U.  S.  WEATHER  BUREAU 

attorneys,  architects,  physicians,  dredging  companies, 
the  Board  of  Trade,  Bankers,  logging  firms,  the  street 
railway,  etc.,  not  to  mention  those  contemplating 
business  or  pleasure  trips,  excursions,  entertainments, 
lawn  parties,  theatre  parties,  and  the  like.  Scores  of 
illustrations  might  be  cited  showing  the  practical  appli- 
cation and  value  of  the  local  weather  service. 


The  Local  Office  of  the  United  States  Weather  Bureau, 
Duluth,  Minnesota. 


Introduction 


The  principal  object  in  compiling  and  arranging  the 
information  contained  in  this  publication  is  to  present 
the  facts  concerning  the  climate  in  the  vicinity  of  Duluth, 
to  refute  the  erroneous  impressions  current  in  the  minds 
of  many,  and  to  indicate  in  some  slight  measure  the 
tremendous  possibilities  in  agriculture  and  other  lines  of 
business  in  this  section,  for  without  question  the  region 
at  the  head  of  the  lakes  is  truly  the  land  of  opportunity. 

Of  course  this  locality  has  some  disagreeable  weath- 
er now  and  then.  What  place  does  not?  As  a  matter  of 
fact  equally  if  not  more  disastrous  wind  and  snow  and 
rain  storms  occur  elsewhere  with  as  great  or  even  greater 
frequency  than  here.  There  are  many  places  having 
winters  just  as  cold  or  even  colder,  and  as  for  the  sum- 
mer and  autumn  seasons  there  are  none  finer  anywhere 
than  ours,  while  at  the  same  time  we  do  not  have  any 
sand  storms,  tornadoes  and  the  like;  nor  are  there  any 
venomous  reptiles  and  insects  to  be  found  hereabouts. 

Some  of  our  people  have  perhaps  been  too  prone  to 
dwell  upon  the  unpleasant  weather  features  of  our  clim- 
ate. When  we  do  have  a  storm  or  cold  wave  of  any 
special  consequence  the  fact  has  been  advertised  far  and 
wide.  It  is  the  exceptional  that  excites  comment,  and 


INTRODUCTION 


particularly   newspaper   comment.     The   average   excel- 
lence of  the  climate  is  accepted  as  a  matter  of  course. 

The  work  of  assembling  the  meteorological  data 
presented  in  this  book  has  been  very  carefully  done,  the 
facts  have  'been  taken  from  the  official  records,  and  the 
manuscript,  charts  and  tables  have  been  reviewed  and 
approved  'by  the  Chief  of  the  U.  S.  Weather  Bureau.. 
The  writer's  opinions  and  conclusions  are  based  on  28 
years  service  in  the  United  States  Weather  Bureau  and 
a  personal  knowledge  of  local  conditions  gained  by  a 
residence  of  16  years  in  Duluth. 

H.  W.  RICHARDSON, 
Local  Forecaster,  U.  S.  Weather  Bureau. 

March  14,  1914. 


On  the  Shore  of  Lake  Superior. 


The  Climate  at  the  Head  of  the  Lakes 
and  its  Relation  to  Agriculture 

Thirty  to  forty  years  ago  the  belief  was  fairly  gen- 
eral that  the  climatic  conditions  in  the  section  adjacent 
to  the  head  of  the  lakes  were  entirely  unsuited  to  the 
growing  of  any  crops  except  potatoes  and  some  of  the 
commoner  varieties  of  garden  truck,  and  then  only  when 
the  season  happened  to  be  especially  propitious.  Even 
as  recently  as  twenty  years  back  comparatively  little 
attention  was  paid,  as  a  rule,  to  either  farming  or  gar- 
dening except  for  purely  personal  needs,  but  from  the 
commercial  standpoint  the  possibilities  of  our  soil  and 
climate  up  to  that  time  had  received  but  scant  considera- 
tion, although  there  were  some  who  began  to  catch  faint 
glimmerings  of  what  might  be  accomplished  if  the  land 
were  cleared  and  rendered  accessible  by  means  of  good 
roads. 

Our  people  were  then  engaged  with  other  and  more 
engrossing  matters.  The  hard  times  which  culminated 
in  1893  were  upon  them,  a  period  that  sorely  tried  men's 
souls.  With  the  return  of  prosperity  attending  renewed 
activities  in  all  lines  of  commerce  during  the  succeeding 
half  dozen  to  ten  years  the  needs  of  our  rapidly  increas- 
ing population  induced  a  number  of  progressive  men  to 
investigate  for  themselves  and  spend  large  sums  of 


THE  CLIMATE  OF  DULUTH 


money  in  demonstration  of  their  faith  in  the  agricultural 
possibilities  of  this  section.  Prominently  among  these 
were  John  G.  Williams,  C.  P.  Craig,  Rt.  Rev. 
James  MicGolrick,  G.  G.  Hartley,  B.  C.  Church, 
W.  C.  Sargent,  S.  F.  Snively,  A.  C.  Jones  and 
B.  F.  Howard.  There  were  some  others,  of  course, 
but  to  those  named  is  due  the  principal  credit 
for  all  the  magnificent  results  being  achieved  now 
or  which  are  in  process  of  development.  They 
talked  agriculture  at  home  and  abroad,  widely  adver- 
tised our  resources,  and  gave  local  agricultural  a  stimulus 
it  never  before  had.  Now  the  number  of  those  is  almost 
legion  who  have  all  the  way  from  1  to  1,000  or  more 
acres  either  wholly  or  partially  under  cultivation.  Space 
permits  only  the  briefest  mention  of  the  innumerable 
and  splendid  back-yard  gardens,  the  fine  dairies  here- 
abouts, the  herds  of  thorough-bred  and  prize  cattle — 
some  of  which  hold  world  records  for  milk  and  butter- 
fat,  the  extensive  and  up-to-date  stock  farms,  successful 
poultry  plants  both  large  and  small,  and  numberless 
specialties  in  the  way  of  garden  and  farm  products. 


VARIETY  OF  CROPS 

Through  the  efforts  of  these  pioneer  enthusiasts  and 
the  excellent  and  highly  organized  co-operation  of  the 
Duluth  Commercial  Club,  agricultural  experiment  sta- 
tions, and  some  of  the  local  railroad  officials,  much  has 
been  acomplished,  enough  at  least  to  clearly  prove  that 
with  the  exercise  of  some  intelligence  and  reasonable 


THE  CLIMATE  OF  DULUTH 


industry  abundant  crops  of  a  great  variety  and  of  the 
very  highest  quality  can  be  successfully  and  very  profit- 
ably grown  in  the  region  adjacent  to  the  head  of  Lake 
Superior. 

It  is  interesting  to  note  that  strawberries  from  Du- 
luth  received  the  highest  award  at  the  St.  Louis  Expo- 
sition, that  the  best  bushel  of  potatoes  grown  in  the 
United  States  in  1911,  exhibited  at  the  American  Land 
Show  in  New  York  City,  was  from  our  county,  that  the 
Allandale  and  Island  Farms  respectively  furnish  the 
finest  head  lettuce  and  celery  that  go  to  the  Chicago  and 
St.  Louis  markets,  while  the  Jean  Duluth  Stock  Farm 
Dairy  and  the  Sebenius  Dairy  compare  with  the  best  in 
the  land.  An  excellent  opportunity  is  afforded  to  make 
large  profits  from  growing  strawberries  for  the  late 
market,  as  they  are  coming  on  locally  when  gone  else- 
where. Corn  for  ensilage  is  being  raised  on  an  extensive 
scale.  Clover,  timothy  and  alfalfa  grow  luxuriantly  here, 
and  the  grass  continues  green  and  succulent  and  plenti- 
ful until  snow  flies.  This  unexcelled  grazing  condition 
is  largely  due  to  the  high  moisture  content  of  the  air  in 
the  late  summer  and  autumn  and  the  increase  in  amount 
of  precipitation  in  September  (principally  the  latter), 
aside  from  such  considerations  as  the  nature  of  the  soil, 
this  being  liberally  provided  with  the  required  plant 
food,  etc.  The  climate  and  soil  favor  practically  all  of 
the  grain  crops.  Gardens,  root  crops,  small  fruits,  ber- 
ries, flowers  and  shrubbery  flourish  here  as  nowhere  else 
on  account  of  soil,  rainfall,  humidity,  temperature,  wind 
and  sunshine  conditions.  Some  varieties  of  apples  and 


10  THE  CLIMATE  OF  DULUTH 

tomatoes  yield  abundantly,  the  size  being  large  and  the 
quality  excellent.  It  is  also  entirely  probable  that  within 
the  next  few  years  grapes  may  be  growing  on  some  of 
our  hillsides.  Potatoes  (the  very  finest  in  quality)  aver- 
age 300  bushels  and  better  per  acre,  much  depending 
upon  good  seed  and  cultivation.  The  writer  knows  per- 
sonally of  an  instance  where  an  average  of  15  bushels  of 
potatoes  is  obtained  annually  from  a  patch  14  feet  by 
about  75  feet  in  area.  The  soil  in  this  case  is  common 
hereabouts,  sandy  loam,  high  in  phosphorus,  well  fer- 
tilized, and  cultivation  is  intensive.  This  is  mentioned 
merely  to  illustrate  the  possibilities  of  backyard  garden- 
ing in  its  relation  to  the  problem  of  the  high  cost  of 
living. 

NO  CHANGE  IN  CLIMATE 

Such  splendid  results  have  led  a  few  to  imagine  that 
our  climate  has  changed  since  pioneer  days.  The  official 
records  of  the  weather  do  not  show  any  appreciable 
change  in  43  years  in  any  of  the  various  elements  which 
comprise  our  climate.  A  permanent  climatic  change 
would  ordinarily  require  ages  of  time  or  else  a  sudden 
and  gigantic  convulsion  seriously  affecting  vast  areas  of 
either  the  earth's  surface  or  that  of  the  sun.  We  have 
no  record  of  either  since  written  history  .began.  The 
aridity  of  vast  areas  of  the  Nile  basin,  for  instance,  is 
perhaps  due  more  to  political  causes  than  any  other,  and 
now  that  irrigation  is  again  possible  there  on  a  large 
and  well  regulated  scale,  its  verdure  will  soon  be  as 
abundant  as  it  was  reputed  to  be  in  the  days  of  the 


THE  CLIMATE  OF  DULUTH  11 

Pharoahs.  Geological  conditions  go  to  prove  also  that 
to  bring  about  a  permanent  change  in  climate  a  period  of 
say  10,000  to  20,000  or  more  years  must  elapse  to  include 
some  of  the  processes  necessary  for  the  effects  of  time 
alone.  Our  winters  are  just  the  same,  on  the  average, 
as  they  were  in  pioneer  days,  and  our  summers  and 
autumns  and  winters  and  springs  are  neither  warmer  nor 
colder  nor  wetter  nor  drier  on  the  average  than  then.  One 
reason  that  impels  us  to  think  that  the  winters  of  early 
days  were  colder  than  in  recent  years  is  because  of  the 
rather  primitive  means  of  combatting  the  cold  then  in 
comparison  with  present  facilities.  Besides,  time  usually 
has  its  influence  in  magnifying  events  of  the  long  ago, 
and  records  obtained  from  the  common  and  cheaply  con- 
structed thermometer  and  its  imperfect  exposure  are  cer- 
tainly unreliable  as  to  accuracy.  Extremes  of  moisture 
and  dryness,  and  heat  and  cold,  quite  often  follow  each 
other  through  the  years  in  the  form  of  rather  uneven 
curves  or  cycles  whose  periods  require  say  5,  10,  15,  20, 
and  sometimes  30  or  more  years  to  consummate  before 
the  occurrence  of  the  inevitable  swing  back  to  normal  or 
the  opposite  condition.  In  general,  the  world  over,  it 
may  be  said  there  is  a  more  or  less  irregular  procession 
of  lean  and  fat  years,  each  covering  varying  periods  of 
time,  in  some  cases  probably  due  to  the  effects  of  sun- 
spot  variations,  changes  in  electrical  potential  of  the 
atmosphere,  varying  amounts  of  volcanic  dust  in  the  air, 
abnormalities  in  storm  paths,  etc. 

The   fact   that   we   can   successfully   and   profitably 
raise    live    stock,    and    grow    vegetables,    fruits,    grains, 


THE  CLIMATE  OF  DULUTH  13 

shrubbery  and  magnificent  flowers  at  the  head  of  the 
la'kes  now  should  really  be  attributed  to  the  processes  of 
development,  selection  and  adaptation  of  species  to  en- 
vironment, a  better  understanding  of  our  climate  and 
soil,  intelligent  cultivation  of  crops,  and  the  proper  care 
of  live  stock. 

The  region  hereabouts  is  one  of  the  most  favored 
and  healthful  and  picturesque  to  be  found  anywhere. 
There  is  an  abundance  of  sunshine  and  moisture  and 
temperature  during  the  growing  season.  Tornadoes 
have  never  occurred  in  this  section,  the  topographic  and 
water  conditions  do  not  favor  their  happening ;  while 
the  real  plains  blizzard  is  practically  an  unknown  feature. 
It  is  true  our  winters  are  cold,  but,  they  are  quite  endur- 
able, and  the  weather  then  is  nearly  always  a  "dry 
cold"  because  of  the  prevalent  westerly  (off  the  land) 
winds.  Besides,  the  outdoor  sports  made  possible  by 
the  low  temperature  and  snow  and  ice  conditions  are 
certainly  compensating  features  which  add  to  our  good 
health  and  pleasure.  At  this  time,  too,  there  is,  on  the 
average,  by  weight,  more  oxygen  in  a  given  volume 
of  air  than  at  other  seasons.  This  increase  in  oxygen 
tends  to  stimulate  the  processes  of  combustion,  which 
in  turn  has  its  energizing  effect  upon  most  forms  of 
animal  life,  including  human  beings.  And  also  because 
of  the  dryness  stock  winters  well  and  even  better  than  in 
many  sections  in  the  central  valleys,  and  eastern  and 
southern  states,  as  ordinarily  we  do  not  have  such  decid- 
ed alterations  of  temperature,  for  the  cold  then  is  rather 
steady,  practically  all  the  precipitation  is  in  the  form  of 


14  THE  CLIMATE  OF  DULUTH 

snow  and  it  is  generally  dry  and  packed  hard,  and  slushy 
snow  is  a  very  rare  condition,  while  severe  sleet  storms 
occur  but  seldom — the  actual  average  is  less  than  once 
per  year.  The  ground  frequently  freezes  to  a  consider- 
able depth,  but  this  is  regarded  as  beneficial  than  other- 
wise, because  of  the  resultant  aeration  of  the  soil  attend- 
ing thawing  operations  in  the  spring,  etc. 

COOL  IN  SUMMER 

During  the  warmer  season  of  the  year  the  extended 
periods  of  debilitating  and  blighting  heat,  so  frequently 
experienced  further  inland,  do  not  invade  this  favored 
region.  Of  course,  rather  warm  spells  occur  now  and 
then,  but  they  are  of  very  brief  duration,  seldom  lasting 
more  than  two  or  three  days  at  a  time.  Maximum  tem- 
peratures varying  from  70°  to  80°  are  quite  the  rule  dur- 
ing the  summer  months,  but  temperatures  of  90°  or  high- 
er occur  only  about  twice  per  summer  in  the  section  im- 
mediately adjacent  to  the  western  end  of  La'ke  Superior. 
The  night  temperatures  in  the  summer  are  generally  so 
cool  that  one  feels  comfortable  sleeping  under  a  blanket. 
It  has  been  stated  that  the  average  coolness  of  the  nights 
in  great  measure  imparts  a  vigor,  freshness  and  crispness 
to  certain  of  the  garden  crops  not  attainable  in  many 
other  sections. 

The  frequent  heavy  dews  and  the  occasional  fog 
periods  materially  assist  the  growth  of  vegetation,  espe- 
cially the  grasses.  From  a  dairy  and  stock  raising  stand- 
point this  region  is  easily  one  of  the  best  in  the  United 
States,  in  fact  it  is  doubtful  if  there  is  better  anywhere. 


THE  CLIMATE  OF  DULUTH  15 

During  the  growing  season,  say  the  144  days  from 
May  10  to  September  30,  the  amount  of  possible  sunshine 
totals  2069.6  hours,  50  to  nearly  75  per  cent,  or  more  of 
which  time  the  sun  is  actually  shining,  the  longest  day 
being  June  21  with  15  hours  and  55  minutes  possible  sun- 
shine. The  grand  total  referred  to  is  approximately  24.5 
hours  more  possible  sunshine  in  the  same  period  than  in 
the  vicinity  of  St.  Paul,  45.2  hours  more  than  at  Des 
Mbines,  and  87.4  hours  more  than  at  St.  Louis.  The  144- 
day  period  is  more  than  sufficient,  in  fact  100  to  125 
days — on  account  of  the  long  hours  of  sunshine  and 
ample  amounts  of  warmth  and  moisture,  rich  soil  and 
proper  cultivation  of  the  latter — will  mature  most  of  our 
crops. 

The  average  date  of  the  last  killing  frost  in  spring 
is  May  3,  and  the  average  of  the  first  in  autumn  is  Oc- 
tober 4,  43-years  record. 

PRECIPITATION 

The  annual  precipitation  is  close  to  30  inches  of 
water  (including  rain,  melted  snow,  etc.),  about  18  inches 
of  which  falls  during  the  growing  season,  ranging  from 
about  30  inches  in  the  wettest  growing  season  to  nearly 
12  inches  in  the  driest.  But  even  in  the  latter  instance 
(season  of  1910,  driest  of  record),  where  crops  were  either 
indifferently  or  well  cultivated  the  yields  ranged  from 
good  to  excellent.  At  this  point  it  might  be  of  interest 
to  mention  the  fact  that  water  an  inch  in  depth  will  meas- 
ure 22,624  gallons  to  the  acre.  This  will  afford  some  idea 
as  to  rainfall  when  considering  quantity.  Of  course  not 


16  THE  CLIMATE  OF  DULUTH 

all  goes  into  the  ground,  such  matters  as  topography  and 
character  of  soil,  run-off  and  evaporation  must  also  be 
considered  in  studying  precipitation  efficiency. 

It  is  of  especial  interest  to  note  that  the  LEAST 
amounts  of  rain  ever  recorded  at  the  head  of  the  lakes 
during  both  the  whole  year  and  the  growing  season, 
represent  practically  the  NORMAL  amounts  for  those 
oeriods  in  the  region  from  the  Dakotas  southward 
through  the  central  and  western  portions  of  Nebraska 
and  Kansas  to  including  central  and  western  Texas. 

About  53  inches  of  snow  (unmelted)  falls  each  win- 
ter, and  the  ground  is  usually  snow  covered  continuously 
from  late  in  November  to  early  in  April.  The  maximum 
accumulated  depths  generally  range  from  5  to  20  inches, 
rarely  exceeding  20  inches  except  in  the  forests  or  where 
drifts  occur.  As  already  stated,  this  snow  is  nearly 
always  dry,  it  packs  hard  and  affords  excellent  sleighing, 
and  its  disappearance  is  rather  gradual  as  a  rule,  by  far 
the  major  portion  of  it  evaporating  into  the  air. 

The  average  hourly  wind  movement  is  mod- 
erate in  winter  and  light  ordinarily  in  summer.  Calms 
are  unusual  and  the  wind  force  is  generally  ample  for  the 
continuous  operation  of  wind  mills  in  cases  where  such 
power  is  preferred  for  use  in  connection  with  pumps  and 
farm  machinery.  Wind  storms  occur  occasionally,  but 
their  strength  and  frequency  compare  favorably  with 
other  sections  of  the  country,  and  tornadoes,  as  already 
stated,  are  an  unknown  feature  in  this  locality.  In  sum- 
mer, autumn  and  winter  there  are  often  long  stretches  of 
the  most  magnificent  weather,  in  fact  nature  seems  to 
have  favored  this  region  in  many  and  unusual  ways. 


THE  CLIMATE  OF  DULUTH  17 

Climatology  of  Duluth,  Saint  Louis 
County,  Minnesota 

Duluth  lies  on  and  at  the  base  of  a  range  of  hills  that 
rise  rather  abruptly  in  the  highest  places  600  and  800 
feet  above  the  level  of  La'ke  Superior,  the  trend  of  the 
range  being  northeast  and  southwest,  but  two  or  three 
miles  back  from  the  water  front  the  country  assumes  the 
character  of  a  more  or  less  level  to  rolling  plateau.  The 
city  proper  extends  along  the  west  banks  of  the  St.  Louis 
River,  Spirit  Lake,  St.  Louis  and  Superior  Bays  and  .Lake 
Superior,  including  Grassy,  Rice's  and  Minnesota  Points. 
Directly  opposite,  on  the  flats  occupying  the  east  banks 
of  the  St.  Louis  River  and  St.  Louis  Bay,  and  the  south 
banks  of  Superior  and  Allouez  Bays,  lies  the  city  of 
Superior,  Wisconsin,  the  two  cities  being  connected  by 
a  swing  bridge  at  the  intersection  of  St.  Louis  and  Super- 
idr  Bays.  The  corporate  limits  of  Duluth  extend  about 
24  miles  northeast  and  southwest,  the  greatest  width 
being  about  3  miles.  The  middle  part  of  the  city  is  in 
lattitude  46°  47'  N,  and  longitude  92°  6'  W. 

The  Duluth  meteorological  station  was  established 
by  the  U.  S.  Signal  Service  on  October  18,  1870.  It  has 
been  in  continuous  operation  since  then,  by  the  Signal 
Service  until  June  30,  1890,  and  after  that  date  by  the 
U.  S.  Weather  Bureau.  Quarters  in  the  Edmonds  Block 
(east  corner  Lake  Avenue  and  Superior  Street)  until 


18  THE  CLIMATE  OF  DULUTH 

June  30,  1882 ;  the  old  St.  Louis  Hotel  Building  from  that 
time  until  November  30,  1884;  the  Metropolitan  Block 
until  January  29,  1895;  and  the  Post  Office  (Govern- 
ment) Building  to  December  31,  1903.  Since  the  latter 
date  the  Weather  Bureau  has  utilized  its  own  building 
(a  two  story  and  basement  structure),  which  faces 
towards  the  harbor  (southeast),  located  on  the  easterly 
side  of  7th  Avenue  West,  between  7th  and  8th  Streets 
and  near  the  hill-top  station  of  the  7th  Avenue  Incline 
Railway.  The  grounds  (100  by  300  feet)  are  of  a  bench- 
like  formation  near  the  top  of  an  otherwise  sloping  hill- 
side. The  view  northeast  around  by  east  to  south  em- 
braces a  range  varying  from  1  to  nearly  70  miles,  and 
includes  Lake  Superior,  the  cities  of  Duluth  and  Super- 
ior, practically  the  whole  harbor,  and  much  of  Wisconsin. 
The  barometer  is  532.17  feet  above  Lake  Superior 
and  1133.37  feet  above  sea  level.  The  rain  and  snow 
gages  are  on  the  ground  about  30  feet  southwest  of 
building  and  mounted  on  a  3  ft.  by  6  ft.  cement  base,  a 
lead-covered  underground  cable  connecting  the  rain 
gage  with  the  register  apparatus  in  offices.  The  ther- 
mometer shelter  is  on  the  ground  50  feet  in  rear  (north- 
west) of  building.  The  shelter  is  the  regulation  pattern, 
mounted  on  galvanized  steel  supports,  the  thermometers 
being  10.5  feet  above  sod.  The  anemometer,  wind  vane 
and  sunshine  recorder  are  all  located  on  the  (flat)  roof 
of  building,  the  anemometer  cups  being  47.1  feet  above 
ground,  and  the  wind  vane  48.3  feet.  The  basement  win- 
dow sills  of  building  are  525.52  feet  above  the  mean  level 
of  Lake  Superior. 


In  a  Duluth  Park. 


20  THE  CLIMATE  OF  DULUTH 


INFLUENCE  OF  LAKE  SUPERIOR 

The  proximity  to  La'ke  Superior,  which  is  the  largest 
and  the  coldest  of  the  Great  Lakes,  materially  influences 
the  local  climate,  especially  in  spring,  summer  and 
autumn  months,  when  the  prevailing  winds  are  from  the 
northeast  and  off  the  Lake.  The  effect  of  the  range  of 
hills  on  the  northwesterly  side  of  Duluth  and  those 
further  to  the  eastward  in  Wisconsin,  which  bound  the 
St.  Louis  River  Valley,  is  also  important,  the  combination 
apparently  acting  so  as  to  promote  an  atmospheric  in- 
draft from  the  Lake,  particularly  in  the  warmer  months. 
Sometimes,  in  mid-summer  the  local  temperature  attend- 
ing the  occasional  strong  northeast  winds  will  be  so  cool 
that  light  overcoats  and  grate  fires  may  be  necessary  in 
those  parts  of  the  city  adjacent  to  the  water  front,  while 
from  1  to  4  miles  back  of  the  range  of  hills  the  tempera- 
ture may  be  fine  and  moderate,  and  5  to  10  miles  still 
further  inland  the  weather  may  be  swelteringly  warm. 

Clear  to  partly  cloudy  weather  is  quite  the  rule  if  the 
northeast  wind  is  light  to  moderate  in  force,  and  the 
temperature  will  then  be  mild  to  moderately  warm ;  but 
fog,  chilly  temperature,  and  rain  usually  attend  strong 
northeast  winds.  In  the  summer  the  land  winds  are  usu- 
ally warm,  southwest  winds  being  attended  by  high 
temperature  generally.  In  the  winter  months  the  land 
winds  (except  south)  are  ordinarily  cold  and  the  Lake 
winds  relatively  warm,  particularly  if  there  is  open  water. 
The  heaviest  snow  storms  occur  in  connection  with 
moderate  to  strong  northeasterly  winds. 


THE  CLIMATE  OF  DULUTH  21 

Many  misrepresentations  concerning  our  local  clim- 
ate have  been  accepted  as  facts  by  the  public  generally, 
and  some  of  these  statements,  on  account  of  exaggeration 
or  by  being  based  on  the  records  of  extremely  inaccurate 
thermometers  with  imperfect  exposure,  border  somewhat 
on  the  ridiculous.  For  instance :  The  writer  has  often 
heard  it  stated  and  in  all  seriousness  that  the  tempera- 
ture in  Duluth  reaches  40°  below  zero  dozens  of  times 
every  winter.  That  is  altogether  wide  of  the  mark. 
Tourists  and  other  visitors  to  our  offices  frequently  make 
such  assertions  as  solemn  fact,  and  the  writer  has  had 
many  inquiries  by  telephone  and  mail  as  to  the  truth 
of  this  legend. 

The  temperature,  as  officially  recorded  by  the 
Weather  Bureau  (including  the  records  of  the  Signal 
Service  regime),  has  reached  40°  below  zero  but  once  in 
43  years,  (ie,  41°,  January  2,  1885.) 

As  a  matter  of  fact  the  official  records  further  show 
that  in  these  43  years  the  temperature  has  fallen  to  30° 
or  more  below  zero  (but  not  to  40°  except  in  the  above 
single  instance)  4  times  in  all  the  Decembers,  26  times  in 
all  the  Januarys,  and  6  times  in  all  the  Februarys,  an 
average  of  not  quite  once  each  winter. 

The  first  zero  temperature  has  occurred  as  early  as 
November  12  (1911)  and  as  late  as  January  11  (1914), 
while  the  last  occurrence  has  been  as  early  as  January 
28  (1878)  and  as  late  as  March  29  (1885  and  1887.) 


22  THE  CLIMATE  OF  DULUTH 

COLD  AND  WARMTH  RELATIVE 

On  the  whole,  atmospheric  cold  and  warmth  are 
somewhat  relative  terms,  and  their  effects  upon  an  in- 
dividual depend  upon  many  things.  In  a  given  locality 
the  cold,  or  the  heat,  may  be  relatively  dry  or  relatively 
moist  on  occasions.  In  the  one  case  a  person  might  be 
exceedingly  uncomfortable  at  a  temperature  of  10°  above 
zero  with  a  high  humidity  and  windy  weather,  and  not 
suffer  any  special  inconvenience  with  a  temperature  of 
25°  below  zero  with  still  air  and  moderate  humidity. 
Much  also  depends  upon  the  personality  of  the  individ- 
ual, his  physical  condition,  his  mental  temperament,  and 
clothing  worn.  A  temperature  of  95°  at  say  50  per  cent, 
relative  humidity  would  not  be  as  uncomfortable  as  a 
temperature  of  75°  or  80°  at  a  relative  humidity  of  95  per 
cent,  or  90  per  cent.,  respectively.  In  the  former  case 
the  warm  and  dry  air  would  evaporate  more  or  less  mois- 
ture from  a  person's  body  and  thus  lower  the  surface 
temperature  somewhat,  while  in  the  latter  instance  the 
evaporation  processes  are  reduced  to  a  minimum  and  the 
resultant  effect  of  warmth  and  moisture  one  of  great 
discomfort. 

In  June,  July  and  August  the  daily  maximum  tem- 
perature averages  about  71°  and  the  minimum  54°. 
About  3  consecutive  days  is  the  usual  limit  on  any  local 
hot  wave  with  temperatures  85°  to  90°,  while  elsewhere 
such  periods  commonly  extend  10  days  to  two  weeks  at 
a  time  with  maximum  temperatures  of  95°  to  100°  or 
higher,  and  with  the  lowest  night  temperature  often  rang- 


THE  CLIMATE  OF  DULUTH 23 

ing  from  75°  to  80°.  At  Duluth,  even  during  the  warm 
waves  referred  to,  the  temperature  at  night  seldom  ex- 
ceeds 65°. 

The  mean  annual  temperature  is  39°.  The  average 
of  the  spring  months  is  37° ;  summer,  63°  ;  autumn,  43°  ; 
winter,  13°.  Average  of  the  warmest  spring,  43°,  1878; 
warmest  summer,  66°,  1878;  warmest  autumn,  48°,  1899; 
mildest  winter,  32°,  1877-8.  Average  of  the  coldest 
spring,  32°,  1888;  coolest  summer,  59°,  1891;  coolest 
autumn,  39°,  1896;  coldest  winter,  5°,  1903-4. 

On  the  average  the  sun  shines  about  55  per  cent,  of 
the  time  possible,  the  greatest  being  65  per  cent,  in  July ; 
and  the  least,  45  per  cent,  in  November  and  December. 
These  amounts  are  more  than  ample  for  all  purposes  and 
compare  favorably  with  other  sections  to  the  eastward 
of  the  Rocky  Mountains.  The  longest  day  is  June  21st 
with  practically  16  hours  of  possible  sunshine,  and  the 
shortest  is  December  21st  with  8  hours  and  30  minutes 
possible  sunshine.  From  May  1  to  September  30  there 
are,  on  the  average,  111  clear  and  partly  cloudy  days,  42 
cloudy  days,  and  61  days  with  .01  inch  or  more  precipita- 
tion. 

The  climate  at  the  head  of  the  lakes  cannot  be  re- 
garded as  humid,  even  in  the  popular  sense.  There  is, 
however,  just  the  right  balance  between  the  temperature 
and  the  water  vapor  actually  present  in  the  atmosphere 
which  makes  for  personal  comfort  in  general,  and  a 
splendid  effect  on  all  forms  of  vegetation  during  the 
growing  season. 


Seasonal  Mean  Temperature  and  Total  I 


EXPLANATORY  NOTES 

Continuous  lines,  mean   temperature  for  period,  degrees  Fat 

Column  1  includes  November,   December,  January,  February 

Column  2  includes  April  and  May. 

REMARKS:  The  above  table  shows  a  rather  decided  ten 
.to  October,  inclusive,  comparing-  similar  periods;  while  the  more 
inclusive  though  the  cold  weather  in  the  winter  months  Is  inc 

The  seasonal  distribution  of  precipitation  is  as  follows:  N 
May,  19  per  cent.;  June,  July  and  August,  39  per  cent.;  Septem 


cipitation,  43  Years.    Duluth,  Minnesota. 


R  "SEASONAL"  CHART. 

aeit.  Shaded  areas,  total  precipitation  for  period,  in  inches. 

d  March.  Column  3  includes  June,  July  and  August. 

Column  4  includes  September  and  October. 

cy  towards  staibility  in  the  mean  temperature  conditions,  April 
jided  variations  usually  occur  in  the  period  November  to  March, 
1  to  be  somewhat  steady. 

mber  to  March,  inclusive,  21  per  cent.,  mostly  snow;  April  and 
and  October,  21  per  cent,  of  the  annual  amount. 


26  THE  CLIMATE  OF  DULUTH 

PRECIPITATION  DISTRIBUTED 

The  precipitation  (rain,  snow,  etc.)  is  well  distrib- 
uted to  meet  the  varying  needs  of  the  seasons.  In  general 
the  heaviest  rainfalls  occur  during  the  warmer  months 
in  connection  with  thunderstorms.  The  greatest  amount 
of  rain  in  any  24  consecutive  hours  was  5.35  inches  on  the 
night  of  July  21-22,  1909.  On  this  occasion  .50  inches 
fell  in  5  minutes  (at  the  rate  of  6.00  inches  per  hour), 
.84  inch  in  10  minutes,  1.07  inches  in  15  minutes,  1.61 
inches  in  30  minutes,  2.37  inches  in  1  hour,  and  2.68 
inches  in  2  hours.  The  greatest  total  precipitation  in  any 
month  was  11.52  inches  in  September,  1881,  and  the  least 
was  0.07  inch  in  December,  1905.  The  greatest  annual 
precipitation  was  45.28  inches  in  1879,  and  the  least  was 
18.11  inches  in  1910.  The  drouth  in  this  latter  year  was 
unprecedented,  115  days  (March  1  to  July  5)  ;  the  rains 
that  actually  fell  were  only  light  and  scattered.  From 
Miarch  1  to 'August  31  the  total  rainfall  was  9.43  inches, 
but  half  the  usual  amount  for  that  period,  while  in  June 
there  was  only  .11  inch,  whereas  that  is  normally  the 
wettest  month,  4.15  inches  being  the  43-year  average. 
Despite  the  unusually  dry  weather  that  year  local  crops 
gave  excellent  returns  where  well  cultivated.  In  this 
year  copious  rains  came  in  September,  which  greatly 
revived  pastures. 

The  annual  snowfall  has  ranged  from  90  inches  in 
1886  to  27  inches  in  1895,  the  average  being  53  inches. 
The  greatest  snowfall  in  any  24  hours  was  13.2  inches  on 
March  9,  1892.  This  storm  was  attended  by  a  50-mile 


THE  CLIMATE  OF  DULUTH  27 

northeast  gale  which  continued  until  the  morning  of  the 
10th. 

The  average  hourly  wind  velocity  is  13  miles,  a  rate 
of  about  .59  pound  pressure  per  square  foot,  which  is 
moderate  and  compares  favorably  with  the  records  for 
other  places.  The  prevailing  wind  direction  is  from  the 
northeast  in  all  months,  except  southwest  in  November, 
December  and  January,  and  northwest  in  February. 
Very  few  gales  of  40  miles  or  more  per  hour  occur  in  the 
late  spring,  summer  or  early  autumn  months,  and  the 
high  winds  in  all  seasons  come  from  either  the  northeast, 
southwest  or  northwest  quadrants,  as  a  rule.  A  strong 
southeast  wind  is  very  uncommon,  in  fact  rare.  The 
most  severe  local  storm  of  record  (as  regards  continuity 
and  effects)  was  the  northeaster  and  snow  storm  on 
November  27-28,  1905.  On  this  occasion  average  hourly 
velocities  of  42  miles  were  maintained  for  29  hours,  50 
to  60  miles  per  hour  for  15  hours,  and  rates  of  60  miles 
per  hour  for  13  hours,  while  the  maximum  rate  for  any 
5  minute  period  was  68  miles.  No  other  local  storm  has 
ever  approached  this  one  as  to  continuity.  Higher  veloci- 
ties have  occurred  in  other  storms,  but  only  for  short 
periods,  while  it  is  rather  seldom  that  the  ordinary  severe 
gale  at  its  height  lasts  more  than  6  to  12  hours.  In  the 
matter  of  gales  and  their  strength,  continuity  and  results, 
our  record  compares  well  with  other  sections,  in  fact 
somewhat  to  our  advantage  when  considering  the  Atlan- 
tic and  Gulf  coasts  and  some  ports  .in  the  Lake  Region. 
Harbor  ice  begins  to  form  locally  late  in  November  and 
disappears  early  in  April.  In  the  lake  the  maximum 


THE  CLIMATE  OF  DULUTH  29 

thickness  of  ice  is  attained  between  February  10  and 
March  25.  The  field  usually  extends  several  miles  down 
the  lake. 

The  average  date  of  opening  local  navigation  is  April 
7th,  ranging  from  March  1  to  May  8,  while  the  date  of 
closing  has  varied  from  December  15  to  February  17. 

April  19  was  the  average  date  of  the  first  arrival  from 
the  lower  lakes,  while  December  5  was  the  average  date 
of  the  last  departure  for  the  lower  lakes  during  the  30 
years  1870  to  1899.  But  in  the  years  1900  to  1913  the 
average  date  of  such  early  arrival  has  been  April  21  and 
the  last  departure  December  15. 

An  examination  of  the  charts  and  tabulated  matter 
given  in  this  book  will  bring  out  many  facts  as  to  tem- 
perature, rain,  snow,  sunshine,  frost,  etc.,  valuable 
to  the  agriculturist,  business  and  professional  men,  the 
student  of  climatology,  and  all  who  may  be  interested  in 
our  climate.  In  many  respects  the  charts  and  tabulated 
data  show  conditions  that  are  practically  the  last  word 
in  the  way  of  extremes,  and  in  view  of  the  length  of  the 
record  it  is  doubtful  if  some  of  these  will  ever  be  ex- 
ceeded, and  perhaps  some  of  the  conditions  shown  will 
continue  indefinitely  as  the  average  and  the  extreme. 

For  certain  other  features  in  regard  to  climatology 
see  the  chapter  on  Climate  at  the  Head  of  the  Lakes  and 
its  Relation  to  Agriculture. 


30 


THE  CLIMATE  OF  DULUTH 


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Lower  line,  average  minimum  temperature  (night), 
Temperature  expressed  in  degrees  Fahrenheit. 
Broad  vertical  lines  indicate  precipitation,  in 
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S      S      0)^      ft     i5      39'13      &o      o      oa; 

Q    t?    fe    S    <J-  S*  ^    ^    <i    OQ    O    55    HS 

w 

* 

THE  CLIMATE  OF  DULUTH 


33 


COMPARATIVE  DATA. 

Monthly  and  Annual  Precipitation   (Inches  and  Hundredtha). 
Dulutb,   Minn. 


Gj 

p 

3 
p, 

O 

03 

3 

ember. 

.0 

ember. 

1 

3 

1 

1 

<P 

fa 

£ 

ft 

1 

3 

3 

bC 

3 

ft 

O 

1 

o 

i 
Q 

g 

1871. 

2.44 

1.32 

1.18 

3.97 

1.40 

3.16 

4.73 

2.14 

3.15 

4.19 

1.47 

2.05 

31.20 

1872. 

0.86 

0.46 

0.85 

1.80 

4.62 

4.46 

5.84 

2.84 

5.01 

0.42 

2.48 

0.48 

30.12 

1873. 

0.75 

0.93 

2.29 

0.30 

3.89 

9.90 

8.50 

2.45 

5.16 

2.31 

1.59 

0.66 

38.73 

1874. 

0.58 

0.61 

1.82 

0.49 

1.80 

10.89 

2.62 

5.62 

5.59 

3.07 

1.97 

1.37 

36.43 

1875. 

0.86 

0.98 

2.17 

2.82 

2.45 

1.84 

0.47 

6.19 

3.77 

2.60 

1.78 

1.10 

27.03 

1876. 

0.69 

1.03 

2.16 

1.99 

3.74 

4.69 

4.03 

3.92 

4.21 

2.15 

2.79 

0.87 

32.27 

1877. 

1.45 

0.10 

0.79 

1.20 

7.24 

4.89 

3.57 

1.48 

5.67 

4.92 

1.05 

1.95 

34.31 

1878. 

0.55 

0.32 

1.34 

5.18 

2.83 

4.81 

2.53 

0.52 

4.68 

3.55 

0.69 

1.09 

28.09 

1879. 

0.72 

1.46 

1.91 

0.90 

7.99 

5.57 

10.42 

1.58 

5.24 

3.95 

1.65 

3.89 

45.28 

1880. 

1.21 

1.57 

2.43 

3.17 

4.31 

10.40 

1.98 

4.35 

1.86 

2.32 

2.91 

1.54 

38.05 

1881. 

1.65 

1.79 

1.46 

1.10 

1.77 

2.52 

1.84 

7.36 

11.52 

3.76 

2.58 

0.20 

37.55 

1882. 

0.57 

2.02 

3.05 

2.51 

7.14 

6.72 

4.92 

3.47 

1.29 

3.56 

1.66 

1.11 

38.02 

1883. 

1.12 

0.78 

0.38 

1.20 

2.07 

4.14 

2.48 

0.98 

2.21 

3.19 

1.63 

3.02 

23.20 

1884. 

0.67 

2.71 

1.32 

3.64 

5.17 

1.13 

3.45 

6.92 

4.70 

3.47 

0.95 

1.22 

35.35 

1885. 

0.61 

0.32 

0.77 

0.89 

1.53 

4.82 

3.46 

2.51 

2.35 

0.79 

1.37 

0.54 

19.96 

1886. 

2.26 

1.81 

1.07 

.97 

1.93 

5.35 

1.48 

2.23 

6.05 

2.45 

2.84 

0.93 

33.37 

1887. 

1.62 

0.81 

0.55 

.58 

4.93 

2.71 

4.17 

1.53 

2.68 

3.34 

1.99 

2.65 

28.56 

1888. 

1.53 

0.24 

0.81 

.97 

4.12 

5.54 

3.86 

4.17 

2.27 

1.68 

0.87 

0.25 

27.31 

1889. 

1.34 

1.38 

1.67 

.35 

2.05 

1.85 

5.53 

7.87 

4.02 

0.34 

0.87 

1.77 

32.04 

1890. 

0.87 

1.09 

1.16 

.75 

2.24 

3.33 

3.51 

3.62 

2.39 

3.03 

0.91 

0.19 

24.09 

1891. 

0.67 

2.07 

3.13 

.71 

2.28 

2.67 

3.82 

3.11 

3.31 

1.83 

1.11 

3.76 

29.47 

1892. 

0.48 

1.46 

2.02 

3.70 

6.54 

5.32 

2.18 

4.28 

0.32 

0.38 

1.69 

0.15 

28.52 

1893. 

1.06 

1.64 

2.28 

3.64 

2.31 

1.59 

3.76 

1.51 

1.04 

1.84 

0.76 

1.91 

23.34 

1894. 

1.51 

0.25 

4.30 

5.85 

5.62 

1.80 

0.92 

1.08 

2.08 

4.99 

1.43 

1.87 

31.70 

1895. 

0.75 

0.48 

0.48 

0.73 

2.13 

4.62 

3.03 

1.67 

5.96 

0.09 

1.65 

0.71 

22.30 

1896. 

1.30 

0.19 

1.59 

4.06 

5.18 

2.00 

1.74 

2.41 

1.00 

3.46 

3.42 

0.84 

27.19 

1897. 

1.48 

2.21 

1.34 

0.72 

1.63 

3.48 

9.29 

3.91 

3.14 

2.11 

0.78 

0.85 

30.94 

1898. 

0.38|  0.89 

0.75 

0.41 

3.30 

3.52 

1.33 

3.39 

1.21 

3.39 

0.94 

0.19 

19.70 

1899. 

0.671  0.66 

0.82 

1.33 

4.66 

7.10 

1.82 

6.18 

2.05 

3.54 

0.61 

1.18 

30.62 

1900. 

0.71  0.28 

0.94 

0.39 

0.62 

1.05 

3.94 

6.15 

4.80 

3.07 

0.54 

0.65 

23.14 

1901. 

0.361  0.72 

1.95 

1.23 

0.97 

9.09 

4.39 

1.70 

2.30 

2.01 

1.28 

0.68 

26.68 

1902. 

0.741  0.70 

0.77 

1.09 

3.89 

3.68 

4.54 

3.30 

1.52 

2.03 

1.85 

2.03 

26.14 

1903. 

0.831  0.67 

1.87 

2.16 

3.54 

0.79 

3.50 

3.80 

4.76 

3.84 

0.95 

1.30 

28.01 

1904. 

0.201  1.25 

1.67 

0.50 

1.48 

3.78 

3.82 

2.47 

3.48 

4.66 

0.24 

0.90 

24.45 

1905. 

0.78 

0.42 

1.05 

1.97 

2.46 

8.75 

4.02 

3.55 

7.72 

2.49 

2.49 

0.07 

35.77 

1906. 

1.78 

0.30 

0.95 

1.51 

3.38 

7.05 

0.97 

3.95 

3.66 

2.34 

1.68 

1.21 

28.78 

1907. 

1.07 

0.71 

1.56 

0.92 

1.60 

1.59 

3.41 

4.28 

6.71 

0.95 

0.53 

0.54 

23.87 

1908. 

0.33 

1.14 

1.54 

2.07 

5.73 

4.48 

5.34 

2.10 

3.55 

2.97 

1  32 

0.48 

31.05 

1909. 

1.021  1.34 

0.78 

2.15 

1.87 

1.33 

10.83 

4.91 

3.28 

2.15 

2.16 

1.83 

33.65 

1910. 

0.80!  1.13 

0.44 

1.40 

1.18 

0.11 

3.89 

2.41 

4.20 

0.81 

1.18 

0.56 

18.11 

1911. 

1.12|  1.89 

1.661  1.09 

3.45 

2.76 

5.83 

3.02 

3.35 

1.37 

2.59 

2.17 

30-.30 

1912. 

0.471  0.27 

0.43 

2.58 

5.00 

1.32 

2.24 

3.25 

1.80 

0.68 

0.21 

2.19 

21.34 

1913. 

0.75 

1.09 

3.25 

1.75 

4.82 

2.03 

6.18 

1.26 

3.32 

3.33 

0.74 

0.17 

28.69 

Me-an 

0.97 

1.01 

1.51|  2.04 

3.44 

4.15 

3.96 

3.38 

3.68 

2.55 

1.49 

1.24 

29.42 

34 


THE  CLIMATE  OF  DULUTH 


AVERAGE  OF   DAILY   MAXIMUM  TEMPERATURES   FOR 

33   YEARS. 
Diilut h,   Minn. 


TO 
>> 

& 

January. 

February. 

March. 

°C 
a 
< 

>> 

d 

*L> 

a 
3 
i-j 

>, 

'B 

1-5 

August. 

September. 

October. 

November. 

December. 

I..  . 

20 

18 

28 

40 

51 

61 

72 

72 

71 

59 

44 

27 

2.  .  . 

17 

19 

29 

39 

52 

59 

70 

73 

69 

59 

45 

26 

3.  .  . 

16 

18 

28 

40 

52 

60 

71 

74 

69 

58 

45 

27 

4.  .. 

19 

18 

26 

41 

53 

63 

70 

74 

72 

56 

43 

29 

5.  .. 

21 

22 

28 

43 

56 

62 

72 

74 

68 

54 

43 

28 

6.  .  . 

20 

24 

30 

41 

52 

62 

74 

75 

68 

56 

42 

29 

7... 

20 

25 

31 

43 

54 

64 

76 

74 

70 

57 

42 

25 

8.  .  . 

20 

23 

31 

43 

55 

64 

74 

75 

68 

56 

41 

26 

9.  .  . 

18 

22 

33 

45 

55 

61 

76 

73 

67 

55 

40 

26 

10.  .. 

18 

26 

30 

43 

54 

61 

76 

75 

65 

54 

38 

29 

11... 

IS 

23 

31 

43 

54 

63 

76 

74 

69 

52 

41 

28 

12.  .  . 

16 

24 

29 

43 

56 

67 

74 

70 

64 

53 

39 

27 

13... 

20 

26 

26 

44 

54 

69 

76 

72 

62 

54 

38 

25 

14... 

17 

24 

26 

44 

54 

66 

76 

70 

63 

54 

36 

25 

15.  .. 

18 

24 

27 

45 

56 

67 

77 

71 

64 

55 

36 

25 

16... 

19 

26 

29 

48 

57 

66 

74 

73 

63 

54 

35 

23 

17... 

21 

28 

30 

49 

57 

69 

75 

73 

61 

52 

35 

22 

18.  .. 

19 

27 

32 

46 

55 

68 

73 

72 

63 

51 

35 

25 

19.  .. 

20 

28 

30 

48 

57 

69 

75 

73 

60 

52 

34 

24 

20.  .  . 

21 

28 

31 

49 

57 

67 

75 

73 

62 

51 

34 

26 

21... 

20 

30 

34 

48 

58 

68 

77 

71 

63 

50 

33 

27 

22.  .. 

18 

30 

35 

51 

55 

70 

76 

70 

63 

50 

30 

27 

23.  .  . 

16 

30 

36 

51 

60 

71 

76 

71 

62 

48 

29 

25 

24.  .  . 

18 

33 

37 

48 

62 

72 

77 

68 

63 

48 

29 

23 

25.  .. 

18 

32 

37 

50 

61 

69 

75 

71 

63 

49 

29 

19 

26..  . 

19 

28 

37 

52 

60 

67 

76 

72 

60 

47 

29 

22 

27.  .. 

19 

32 

35 

54 

60 

69 

76 

71 

60 

46 

28 

20 

28.  .  . 

20 

33 

36 

51 

59 

69 

75 

71 

59 

46 

27 

23 

29..  . 

20 

38 

50 

62 

73 

76 

71 

61 

43 

24 

'21 

30... 

20 

38 

50 

59 

70 

77 

70 

61 

46 

25 

21 

31... 

18 

39 

60 

73 

68 

45 

21 

Mean 

19 

26 

32 

46 

56 

66 

75 

72 

64 

52 

36 

25 

THE  CLIMATE  OF  DULUTH 


35 


AVERAGE    OF    DAILY    MINIMUM   TEMPERATURES    FOR 

33  YEARS. 
Duliii  h.   Minn.        e 


w 
h 

<ri 

p 

January. 

February. 

March. 

°E 
a 

«s 

>> 

1 

tf 

c 

3 

1-3 

£ 

3 

1-3 

August. 

September. 

October. 

November. 

December. 

1.  .  . 

3 

-3 

12 

23 

35 

45 

53 

58 

55 

44 

32 

13 

2.  .  . 

-1 

0 

12 

24 

35 

45 

54 

58 

55 

45 

32 

13 

3.  .  . 

0 

-1 

11 

26 

36 

45 

54 

58 

53 

43 

32 

14 

4.  .  . 

1 

-4 

9 

26 

37 

46 

54 

58 

53 

43 

32 

13 

5.  .. 

6 

0 

11 

28 

37 

45 

54 

59 

54 

41 

31 

15 

6.  .. 

6 

4 

11 

28 

37 

44 

56 

59 

53 

42 

30 

13 

7.  .  . 

3 

4 

13 

27 

37 

46 

57 

59 

52 

43 

31 

10 

8.  ., 

1 

4 

15 

29 

40 

47 

57 

59 

52 

42 

29 

11 

9.  .  . 

-1 

1 

18 

31 

40 

46 

57 

59 

52 

41 

28 

13 

10.  .  . 

2 

2 

15 

30 

39 

45 

58 

58 

52 

41 

28 

15 

11.  .. 

0 

3 

16 

30 

38 

46 

57 

58 

51 

41 

27 

14 

12.  .  . 

0 

2 

13 

30 

40 

48 

57 

57 

50 

41 

26 

13 

13.  .  . 

0 

4 

9 

31 

38 

49 

57 

57 

48 

40 

25 

11 

14.  .  . 

0 

2 

10 

31 

39 

49 

58 

58 

50 

41 

24 

9 

15.  .  . 

1 

2 

10 

30 

38 

49 

58 

57 

50 

40 

25 

9 

16.  .. 

2 

3 

11 

31 

38 

49 

57 

59 

48 

40 

23 

9 

1  7  ... 

3 

6 

13 

32 

40 

50 

57 

58 

47 

39 

20 

6 

18.  .  . 

2 

4 

15 

33 

40 

49 

57 

57 

47 

38 

21 

11 

19.  .  . 

2 

5 

13 

33 

41 

52 

57 

58 

47 

36 

21 

9 

20.  .. 

6 

5 

15 

34 

41 

52 

58 

58 

46 

37 

20 

12 

21.  .. 

1 

7 

16 

34 

41 

51 

58 

57 

48 

37 

21 

13 

22.  .  . 

1 

7 

17 

34 

42 

51 

58 

56 

48 

37 

19 

14 

23.  .. 

-1 

8 

15 

35 

42 

52 

58 

56 

47 

37 

16 

9 

24.  .  . 

3 

7 

21 

34 

43 

53 

58 

57 

47 

35 

14 

8 

25.  .  . 

1 

8 

20 

34 

43 

53 

58 

56 

47 

35 

16 

5 

26.  .  . 

1 

8 

21 

36 

42 

51 

58 

57 

46 

35 

16 

4 

27.  .  . 

2 

9 

21 

36 

43 

51 

58 

57 

45 

36 

15 

4 

28.  .  . 

1 

10 

21 

36 

43 

52 

58 

58 

44 

34 

13 

8 

29.  .. 

1 

. 

22 

35 

43 

52 

58 

57 

45 

33 

10 

6 

30.  ..1   2 

24 

34 

44 

53 

58 

56 

46 

33 

10 

3 

31.  .  . 

1 

25 

44 

59 

55 

32 

5 

Mean 

2 

4 

15 

31 

40 

49 

57 

58 

49 

39 

23 

10 

36 


THE  CLIMATE  OF  DULUTH 


TEMPERATURE,    DULUTH,    MINN. 

Mean  of  Maxima  and  Mean  of  Minima    (Monthly  and  Annual), 
in  Degrees  Fahrenheit. 


Jan. 

Feb. 

Mar. 

April 

May 

June 

Year. 

Max.Min 

Max.Min. 

Max.Min. 

Max.Min. 

Max.  Min. 

Max.  Min. 

1874.  . 

62  43 

66  50 

1875.  . 

~9  -14 

l<f  -14 

29   7 

44  26 

58  39 

65  47 

1876.  . 

24   3 

20   1 

29   9 

46  30 

57  38 

64  45 

1877.  . 

19  -2 

39  23 

31  12 

48  32 

58   42 

64  47 

1878.  . 

28  13 

38  24 

46  31 

51  37 

56  40 

67  51 

1879.  . 

23   2 

19  -1 

36  16 

49   30 

57   40 

69  49 

1880.  . 

31   11 

24   1 

30   9 

45   29 

62  40 

69  51 

1881.  . 

12  -2 

22   8 

35   21 

47  29 

59   44 

65  49 

1882.  . 

24   6 

34   17 

35   20 

45  32 

55   38 

68  51 

1883.  . 

11  -9 

23   1 

32  12 

48  33 

52  39 

68  50 

1884.   . 

15  -6 

15  -2 

30  11 

42  31 

58   41 

65  50 

1885.  . 

8  -12 

15  -6 

27   8 

46   28 

56  39 

68  50 

1886.  . 

14  -2 

24   3 

35   15 

46  31 

65   43 

69   49 

1887.  . 

12  -9 

20   0 

33  12 

47   28 

58  42 

65   48 

1888.  . 

12  -7 

22   3 

25   7 

45  28 

52  35 

65   46 

1889.  . 

26   13 

18   1 

41  26 

48  34 

58  40 

66   50 

1890.  . 

20   5 

25   8 

30  13 

48  33 

50  36 

66   49 

1891.  . 

28   13 

20   -4 

26   12 

47   32 

58  39 

61  47 

1892.   . 

17   0 

24   11 

31  16 

40  29 

50  39 

63  49 

1893.  . 

12  -2 

16   0 

31   14 

38   29 

54  40 

68  52 

1894.   . 

20   5 

24   6 

36   23 

43   33 

56  40 

73  52 

1895.   . 

15   0 

21   4 

32  15 

48  36 

59  41 

66   49 

1896.   . 

20   7 

26   7 

30  14 

45   32 

62   44 

70  52 

1897.   . 

18    1 

24  13 

29  15 

48   32 

57  40 

63   46 

1898.  . 

26   12 

25   10 

38  23 

47  34 

58  43 

65  48 

1899.  . 

18   1 

15  -2 

23   7 

47  33 

54  39 

67  49 

1900.  . 

26   10 

16  -2 

29   14 

.53  36 

63   44 

68  50 

1901.  . 

21   5 

18   3 

31   18 

47   35 

58  42 

65  49 

1902.  . 

25   8 

25   11 

38   25 

46   32 

55  40 

64  46 

1903.  . 

21    4 

24   5 

37   24 

46   34 

54  41 

68  50 

1904.  . 

13  -4 

10  -8 

26   12 

41  '  27 

57  40 

65   47 

1905.  . 

14  -3 

17   0 

33  19 

47  29 

55  39 

64  47 

1906.  . 

26   8 

21    1 

26   11 

52   35 

53   37 

66   48 

1907.  . 

12  -6 

21    2 

33   17 

38  23 

46  31 

68  48 

1908.  . 

25   5 

24   9 

32   15 

48   29 

56  39 

65   48 

1909.  . 

19   1 

20   5 

32  18 

40   24 

53  36 

70  48 

1910.  . 

21   6 

18  -1 

48  27 

50  33 

56  37 

77   54 

1911.  . 

16  -6 

26   8 

37  19 

46  30 

61  41 

70  48 

1912.  . 

1  -15 

17   1 

27  10 

47  30 

54  39 

68  49 

1913.  . 

16  -4 

14  -3 

25   9 

49   32 

55  37 

70  49 

Means.  . 

18   1 

22   4 

32  15 

46  31 

47  40 

69   48 

High... 

31  13 

39   24 

48   31 

53   37 

65   44 

77  54 

Low  

1  -15 

10  -14 

23   7 

38  23 

46   31 

61  45 

NOTE:  During  the  period  Oct.  18,  1870,  to  December  31,  1903, 
the  height  of  the  thermometers  above  lake  level  (which  is  601.2 
feet  above  sea  level)  varied  from  about  43  to  about  175  feet,  ac- 
cording to  location  of  the  office.  Since  January  1,  1904,  at 
Weather  Bureau  Building,  the  height  of  the  thermometers  has 
been  substantially  540  feet  above  mean  lake  level,  while  that  of 
the  other  Instruments  has  also  differed  accordingly.  These 


THE  CLIMATE  OF  DULUTH 


37 


TEMPERATURE,    DULUTH,   MINN.    (Continued) 

Mean  of  Maxima  and  Mean   of  Minima    (Monthly  and   Annual), 

in  Degrees  Fahrenheit. 


1         1 

July 
Max.Min 

Aug. 
Max.  Min 

Sept. 
|Max.  Min 

Oct.     Nov. 
Max.  Min.  [Max.  Min. 

Dec. 
Max.Min 

Annual 
Max.  Min. 

78  58 

71  58 

67  52 

54   41 

34  18 

26   5 



77  57 

72   57 

62  47 

48   34 

32  14 

31   16 

45   26 

76   55 

74   58 

62   49 

48  35 

36   25 

19  -3 

46  29 

77   59 

78  61 

67  53 

51   40 

38  26 

38   27 

51  35 

79   62 

79   60 

65   48 

50  35 

43  29 

23   9 

52   S7 

78   58 

76  59 

62  46 

58   44 

36   21 

16  -3 

48  30 

76  57 

72  58 

65   49 

50  38 

26   14 

19   5 

47  30 

81   62 

74  61 

63   50 

52   39 

34  20 

34  18 

48  33 

70  54 

70  58 

65   53 

55   44 

39   29 

23   8 

48  34 

74  67 

70  56 

62   48 

50  39 

37  21 

24   7 

46  29 

70  56 

71   58 

65   52 

55   40 

37  21 

17   3 

45   30 

74   57 

70  56 

62  48 

50  39 

37  21 

24   7 

46  29 

76   58 

73   57 

60   44 

58   39 

37  21 

18    0 

48   30 

77   58 

72  54 

63   49 

50   33 

38  22 

27   10 

47  29 

75  55 

73   54 

64   48 

49   38 

40  29 

32  18 

46   29 

72  56 

72  57 

62   48 

48   36 

37  25 

31   20 

48   34 

75   58 

68  54 

64   46 

50  40 

41   28 

SO  16 

47  32 

70  53 

69  56 

70  53 

53   40 

31   19 

34  20 

47   32 

79  60 

75   59 

67   52 

56   42 

32   21 

20   8 

46   32 

76   57\ 

72  57 

64  49 

51  39 

34   23 

19   4 

45  30 

79  58 

73   57 

68   52 

52   41 

32  20 

32  20 

49  34 

70  55 

73   58 

65   50 

49   35 

35   23 

26   14 

46   32 

76  57 

74  56 

62   47 

48   36 

27   14 

28   16 

47  32 

74  58 

71   57 

70  55 

54  43 

32  '  20 

21   7 

47  32 

75  57 

70  58 

68   50 

50  38 

36   22 

22   5 

48  34 

73   56 

71   59 

62   48 

54   42 

46   35 

26  13 

46   32 

72  57 

75  60 

66  51 

60  48 

33  22 

26   13 

49   34 

74  58 

74  61 

64  51 

56   41 

36   23 

21   8 

47   33 

74  58 

68  56 

60  46 

53   40 

39   29 

24   9 

48   33 

73   56 

66   54 

62   47 

56   41 

35  21 

18   2 

47  32 

71  53 

70  52 

59   45 

50  38 

42   27 

22   7 

44   28 

71   54 

73   57 

66   51 

48   34 

38   23 

27   13 

46   30 

74   56 

72  56 

70  52 

49   35 

35   25 

22   8 

47  31 

76   55 

69   52 

58   45 

51   35 

37   24 

27  12 

45  28 

73   55 

71   53 

70  51 

53   38 

40  35 

23   8 

48   31 

73  55 

72  57 

64   46 

49  36 

40  27 

18   6 

46   30 

77  58 

71   54 

64   47 

56   39 

29  19 

21   4 

49  31 

75   54 

70   52 

61   46 

49   35 

29  14 

26  14 

47  30 

72  54 

64  51 

63   47 

56   37 

40  24 

27   9 

44  28 

69  52 

70  54 

62  46 

49  32 

43  28 

34  19 

46  29 

74  56 

71   57 

64  49    52  38 

36   23 

25  10 

47  31 

81   62 

79  61 

70  55 

60   48 

46   35 

38   27 

52   37 

69   52 

64  51 

58   44 

48   32 

26   14 

16  -3 

44   26 

changes  in  elevation  have  had  some  effect  on  temperature  ex- 
tremes and  wind  velocities,  but  the  present  location  is  prac- 
tically ideal  for  all  purposes. 

The  12  years,  1874-1888,  have  rather  more  than  the  usual 
number  of  low  minima  for  the  winter  months.  It  was  a  cold 
series  of  years  which  may  now  again  begin  to  recur. 


38 


THE  CLIMATE  OF  DULUTH 


COMPARATIVE  DATA. 

Monthly  and  Annual  Mean  Temperature    (degrees  Fahrenheit). 
Duluth,  Minn. 


i 

{* 

January. 

February. 

March. 

I 

>, 

aS 

c 

3 

Hj 

>, 

3 

HS 

August. 

September.  | 

October. 

November. 

December. 

Annual. 

1871... 

13 

17 

29 

39 

53 

60 

66 

64 

56 

45 

27 

7 

40 

1872.  .  . 

13 

18 

18 

37 

46 

60 

67 

68 

56 

47 

27 

5 

38 

1873.  .  . 

8 

15 

26 

38 

46 

58 

65 

65 

53 

43 

24 

20 

38 

1874.  .. 

13 

16 

24 

33 

52 

58 

68 

64 

59 

47 

26 

15 

40 

1875.  .  . 

-3 

-2 

18 

35 

49 

56 

67 

64 

55 

41 

23 

23 

36 

1876.  .  . 

14 

10 

19 

38 

48 

55 

65 

66 

55 

41 

31 

8 

38 

1877.  .  . 

9 

31 

22 

40 

50 

56 

68 

69 

60 

45 

32 

33 

43 

1878.  .. 

20 

31 

38 

44 

48 

59 

70 

70 

56 

42 

36 

16 

44 

1879.  .  . 

13 

9 

26 

39 

49 

59 

68 

67 

54 

51 

28 

6 

39 

1880.  .. 

21 

13 

19 

37 

51 

60 

66 

65 

57 

44 

20 

12 

39 

1881.  .. 

5 

15 

28 

38 

51 

57 

72 

68 

56 

45 

27 

26 

41 

1882.  .  . 

15 

25 

27 

39 

46 

59 

62 

64 

59 

49 

34 

16 

41 

1883.  .  . 

1 

12 

22 

40 

45 

59 

66 

63 

55 

44 

29 

15 

38 

1884.  .. 

4 

6 

21 

36 

50 

58 

63 

64 

58 

47 

29 

10 

37 

1885.  .  . 

-2 

4 

17 

37 

47 

58 

65 

61 

56 

43 

32 

20 

37 

1886.  .. 

6 

14 

25 

38 

54 

59 

67 

65 

52 

49 

29 

9 

39 

1887.  .  . 

2 

10 

22 

37 

50 

56 

68 

63 

56 

41 

30 

18 

38 

1888.  .  . 

2 

13 

16 

37 

44 

56 

65 

64 

56 

44 

34 

25 

38 

1389.  .  . 

20 

9 

33 

41 

49 

58 

64 

65 

55 

42 

31 

26 

41 

1890.  .. 

12 

17 

22 

41 

43 

58 

66 

61 

55 

45 

34 

23 

40 

1891.  .  . 

20 

12 

20 

39 

49 

54 

61 

62 

62 

46 

25 

27 

40 

1892.  .  . 

8 

18 

24 

35 

44 

56 

70 

67 

59 

49 

26 

14 

39 

1893.  .  . 

5 

8 

23 

33 

47 

60 

66 

65 

56 

45 

29 

11 

37 

1894.  .  . 

13 

15 

29 

38 

48 

63 

69 

65 

60 

47 

26 

26 

42 

1895.  .  . 

8 

13 

23 

42 

50 

57 

62 

65 

58 

42 

29 

20 

39 

1896.  .  . 

13 

16 

22 

38 

53 

61 

66 

65 

55 

42 

21 

22 

40 

1897.  .  . 

9 

19 

22 

40 

48 

54 

66 

64 

63 

49 

26 

14 

40 

1898.  .  . 

19 

17 

31 

40 

51 

57 

66 

64 

59 

44 

29 

13 

41 

1899.  .. 

9 

6 

15 

40 

47 

58 

65 

65 

55 

48 

41 

19 

39 

1900.  .  . 

18 

7 

22 

45 

53 

59 

65 

68 

59 

54 

27 

20 

41 

1901.  .  . 

13 

11 

25 

41 

45 

57 

66 

68 

57 

48 

29 

15 

39 

1902.  .  . 

17 

18 

32 

39 

48 

55 

66 

62 

53 

46 

34 

16 

41 

1903.  .. 

12 

14 

30 

40   47 

59 

64 

60 

55 

48 

28 

10 

39 

1904.  .. 

4 

1 

19 

34 

49 

56 

62 

61 

52 

44 

34 

14 

36 

1905.  .  . 

6 

9 

26 

38 

47 

56 

63 

65 

59 

41 

30 

20 

38 

1906.  .  . 

17 

11 

18 

43 

45 

57 

65 

64 

61 

42 

30 

15 

39 

1907.  .  . 

3 

12 

25 

31 

39 

58 

66 

60 

52 

43 

30 

20 

36 

1908.  .  . 

15 

16 

23 

39 

48 

57 

64 

62 

60 

46 

32 

16 

40 

1909.  .  . 

10 

10 

25 

32 

45 

59 

64 

65 

55 

42 

34 

12 

38 

1910... 

13 

8 

37 

41 

47 

66 

67 

63 

56 

48 

24 

13 

40 

1911.  ..1   5 

17 

28 

38 

51 

59 

65 

61 

53 

42 

21 

20 

38 

1912.  .. 

-7 

9 

19 

39 

47 

58 

63 

57 

55 

47 

32 

18 

36 

1913... 

.  6 

6 

17 

40 

46 

59 

60 

62 

54 

41 

36 

27 

38 

Mean  .  . 

10 

13 

24 

38 

48 

58 

66 

64 

56 

45 

29 

17 

39 

THE  CLIMATE  OF  DULUTH 


39 


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THE  CLIMATE  OF  DULUTH 


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42 


THE  CLIMATE  OF  DULUTH 


Normal  Mean  Temperature  and  Precipitation. 

Continuous  curve,  Mean  Temperature,  degrees  Fahrenheit. 

Shaded  areas,  Mean  Precipitation  in  inches. 

DULUTH,  MINN. 


Jan  Feb  Mchi  April  lay  L  ^in{julLAug[Sep|OcilNov 


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May 


Jun 


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Aug  Sep 


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THE  CLIMATE  OF  DULUTH 


43 


Normal  Mean  Temperature  and  Precipitation. 

Continuous  curve,  Mean  Temperature,  degrees  Fahrenheit, 
Shaded  areas,  Mean  Precipitation  in  inches. 


MISSOURI  VALLEY  STATES. 


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44 


THE  CLIMATE  OF  DULUTH 


COMPARATIVE    PRECIPITATION,    IN    INCHES. 


DISTRICT 

Aug. 

Sept. 

Oct. 

Aug. 
Sept.  and 
Oct. 

August 
and 
September 

September 
and 
October 

DULUTH, 
OHIO  VALLEY 
STATES, 
UPPER  MISSISSIPPI 
VALLEY  STATES, 

3.4 
3.4 
3.2 

3.7 
2.8 
2.9 

2.6 
2.0 
2.4 

9.7 

8.2 
8.5 

7.1 
6.2 
6.1 

6.3 

4.8 
5.3 

MISSOURI  VALLEY, 

3.4 

2.7 

3.3 

9.4 

6.1 

6.0 

NORTH  DAKOTA,      - 

2.3 

1.4 

1.3 

5.0 

3.7 

2.7 

The  foregoing1  table  of  average  rainfall  explains,  in  great 
measure,  why  grass  is  green  and  luxuriant  at  the  head  of  the 
lakes  during  the  Autumn  months,  while  at  the  same  time  in  other 
sections  pastures  may  be  brown  and  bare  and  stock  feeding  nec- 
essary. Note  the  moderate  mean  temperature  at  Duluth  in  com- 
parison with  the  high  mean  temperatures  in  June,  July,  August 
and  September,  in  the  Ohio,  Upper  Mississippi  and  Missouri  Val- 
ley States  as  shown  on  Chart,  pages  42.  43. 

The  Ohio  Valley  averages  (see  also  Chart,  page  42-)  include 
the  following  places:  Chattanooga,  Knoxville,  Memphis,  Nashville, 
Lexington,  Louisville,  Evansville,  Indianapolis,  Cincinnati,  Colum- 
bus, Dayton,  Pittsburg,  Parkersburg  and  Elkins. 

The  Upper  Mississippi  Valley  averages  include:  Minneapolis, 
St.  Paul,  La  Crosse,  Madison,  Charles  City,  Davenport,  Des  Moines, 
Dubuque.  Keokuk,  Cairo,  La  Salle,  Peoria,  Springfield  (111.),  Han- 
nibal and  St.  Louis. 

The  Missouri  Valley  averages  include:  Columbia  (Mo.),  Kansas 
City,  St.  Joseph,  Springfield  (Mo.),  lola,  Topeka,  Lincoln,  Omaha, 
Valentine,  Sioux  City,  Pierre,  Huron  and  Yankton. 

The  North  Dakota  averages  include;  Moorhead,  Bismarck, 
Devils  Lake  and  Williston. 


SUMMER  STATISTICS 
Comparative  Sunshine  Conditions 


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41°-35' 
38°-38' 


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10 
19 
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May 
May 
Apr. 
Apr. 


Oct.  4 

Oct.  5 

Oct.  8 

Oct.  29 


Comparative  Temperature  Conditions 


, 

June 

July 

August 

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DULUTH,  MINN.    . 

58° 

69° 

48° 

66° 

74° 

56° 

64° 

71° 

57° 

2 

St.   Paul,    Minn  

66° 

77° 

58° 

74° 

83° 

62° 

72° 

80° 

60° 

3 

Bismarck,    N.    D.  .  . 

64° 

75° 

53° 

70° 

82° 

58° 

68° 

81° 

55° 



6 

Milwaukee,   Wis.    . 

64° 

72° 

55° 

70° 

78° 

62° 

69° 

76° 

61° 

10 

Chicago,    111  

66° 

74° 

59° 

72° 

80° 

65° 

71° 

77° 

65° 

2 

Detroit,    Mich.     ... 

67° 

76° 

58  ° 

72° 

81° 

63° 

70° 

79° 

61° 

8 

Cleveland,    Ohio    .  . 

67° 

75° 

59° 

72° 

80° 

64° 

70° 

77° 

62° 

5 

Buffalo,    N.    Y  ..... 

65° 

72° 

57° 

70° 

76° 

63° 

68° 

76° 

61° 

1 

New    York   City.  .  . 

69° 

77° 

51° 

74° 

82° 

67° 

73° 

80° 

66° 

8 

Boston,   'Mass  

66° 

75° 

J7  ° 

72° 

80° 

63° 

70° 

78° 

62° 

9 

Washington,   D.  C. 

73° 

83° 

!3  ° 

77° 

87° 

68° 

75° 

84° 

66° 

8 

Pittsburgh,   Pa.  ..  . 

71° 

82° 

61° 

75° 

85° 

65° 

73° 

83° 

63° 



4 

Louisville,   Ky.    .  .  . 

75° 

84° 

66° 

79° 

88° 

69° 

77° 

86° 

67° 



17 

Memphis,   Tenn.    .  . 

78° 

87° 

69° 

81° 

90° 

72° 

80° 

88° 

71° 



10 

St.    Louis.    Mo  

76° 

84° 

!6° 

80° 

88° 

71° 

78° 

86° 

69° 



15 

Kansas  City,   Mo.  . 

.74°|83° 

54  ° 

78° 

87° 

69° 

76° 

86° 

67° 



12 

Omaha,   Neb  

72°|81° 

62° 

76° 

86° 

67° 

74° 

84° 

55  ° 



6 

Atlanta,    Ga  

176°  85° 

67° 

78° 

87° 

70° 

77° 

85° 

69° 



5 

Jacksonville,    Fla.     |80°|89° 

72° 

82° 

91° 

74° 

82° 

90° 

74° 



14 

New  Orleans,   La.  .||81°|87° 

74° 

83° 

89° 

76° 

82° 

88° 

75° 

— 

4 

The  foregoing1  figmres  afford  an  interesting  comparison  between 
Duluth  and  other  sections  of  the  country  to  the  eastward  of  the 
Rocky  Mountains  as  regards  average  temperature  conditions. 
These  averages  cover  periods  of  thirty  years  or  more  at  places 
selected.  A  temperature  of  90°  or  higher  (in  the  shade)  is  an 
uncommon  occurrence  at  Duluth,  in  fact  there  have  been  numerous 
summers  without  such  temperature.  The  locality  at  the  head  of 
the  lakes  is  peculiarly  free  from  the  10  days  to  2  weeks  periods  of 
debilitating  and  blistering  heat  that  afflicts  other  section  at  vari- 
us  times  during  the  summer.  Our  summer  weather  is  accompanied 
by  much  clear  sky,  the  temperature  during  the  day  is  comfortably 
warm  without  being  hot  and  the  nights  are  delightfully  cool.  One 
can  always  get  a  good  night's  rest  and  blankets  are  generally 
necessary. 


46 


THE  CLIMATE  OF  DULUTH 


SUNSHINE  CONDITIONS,   SELECTED   DATES. 

(Growing  Season.) 

Mnliiili.    Minn. 


Dates. 

Time  of 
Sunrise 

* 

Time  of 
Sunset 

* 

Period  of 
Possible 
Sunlight 

May    1st      

4:52  a.  m. 

7*18  p  m 

14  hrs  26  mins 

May    10th    

4:37  a.  m. 

7:30  p.  m 

14  hrs  53  mins. 

May    20th    

4:26  a.  m. 

7:42  'p.  m. 

15  hrs.  16  mins. 

May    31st 

4-17  a  m 

7  '54   p  m 

15  hrs  37  mins 

Juno   1st          

4'16  a  m 

7'55   p   m 

15  hrs  39  mins 

June  10th    

4:13  a  m. 

8:02  p.  m. 

15  hrs.  49  mins. 

June    21st  t     

4:12  a.  m. 

8:07  p.  m. 

15  hrs.  55  mins. 

June   30th    

4:16  a.  m. 

8:07  p.  m. 

15  hrs.  51  mins. 

July   1st  J 

4-17  a  m 

8  '06  p  m 

15  hrs  49  mins. 

July    10th 

4-23   a  m 

8'03  p  m 

15  hrs.  40  mins. 

July    20th               .      ... 

4  '33  a.  m 

7'55  p.  m. 

15  hrs.  22  mins. 

July    31st  -^  

4:46  a.  m. 

7:43  p.  m. 

14  hrs.  57  mins. 

August  1st 

4-47  a  m 

7-41  p.  m 

14  hrs.  54  mins. 

August    10th    .                   ... 

4*58  a  m 

7  '28  ip.  m 

14  hrs  30  mins. 

August    20th           

5:12  a.  m. 

7:11  p.m. 

13  hrs.  59  mins. 

August    31st     
September  1st 

5:26  a.m. 
5*27  a  m 

6:50  p.  m. 
6  :48  p.  m. 

13  hrs.  24  mins. 
13  hrs.  21  mins. 

September  10th   
September  22nd  §    
September    30th    

5:39  a.  m. 
5:55  a.  m. 
6:06  a.  m. 

6:31  p.  m. 
6:06   p.  m. 
5:50  p.  m. 

12  hrs.  52  mins. 
12  hrs.  11  mins. 
11  hrs.  44  mins. 

*Central  Standard  time. 

tSummer  Solstice,  longest  day. 

tAphelion,  greatest  distance  from  sun. 

§Autumnal  Equinox. 

The  periods  of  morning  and  evening  twilight  in  this  latitude 
are  anywhere  from  1  to  about  2  hours  each,  much  depending  upon 
the  state  of  the  atmosphere. 


THE  CLIMATE  OF  DULUTH 


47 


SUNSHINE  CONDITIONS,  SELECTED  DATES. 

(October  1  to  April  30.) 

Duluth,   Minn. 


Dates. 

Time  of 
Sunrise 

* 

Time  of 
Sunset 

* 

Period  of 
Possible 
Sunlight 

October    1st 

6'07  a  m 

5  '48   p  m 

11  hrs  41  mins 

October    10th 

6  *19  a  m 

5  '31  p  m 

11  hrs  12  mins 

Octoiber   20th           .               ... 

6'33  a  m 

5*12   a   m 

10  hrs  39  mins 

October    31st      

6*50  a  .m. 

4'54  a  m 

10  hrs     4  mins. 

November   1st 

6  '51  a  m 

4  '52   p   m 

10  hrs     1  min 

Novern'ber  10th 

7-04   a  m 

4  '40   p   m 

9  hrs  36  mins 

November     20th            .    . 

7'19  a  m 

4-29   p   m 

9  hrs  10  mins 

November    30th     

7:32  a  m 

4'21   p   m 

8  hrs   49  mins. 

December    1st 

7-34  a  m 

4-21  p  m 

8  hrs  47  mins 

Decerrrber   10th    .  .        . 

7-43   a  m 

4'19  p  m 

8  hrs  36  mins 

December    21st  t    

7:51  a.  m. 

4*21   p  m 

8  hrs   30  mins. 

December    31st 

7  '54  <a  m 

4  -28   p  m 

8  hrs   34  mins 

January    1st  J             

7  '54  a  m 

4  '30   p  m 

8  hrs  36  mins 

January  10th    

7'52  a  m 

4  '39  p  m 

8  hrs  47  mins 

January  20th   

7:46  a.  m. 

4'53  p.  m 

9  hrs     7  mins 

January  31st 

7'34  a  m 

5  '09  p  m 

9  hrs  35  mins 

February  1st    

7  :33  a  m 

5*10  p  m 

9  hrs  37  mins 

February  10th   

7:21  a  m. 

5'24   p  m 

10  hrs     3  mins 

February    20th 

7'04  a  m 

5  '40  p  m 

10  hrs  36  mins 

February    28th 

6  '50  a  m 

5  '52  p  m 

11  hr®     2  mins 

February    29th    

6'48  a  m 

5'53  p  m 

11  hrs     5  mins 

March    1st 

6  '48  a  m 

5  •  5  3  p  m 

11  hrs     5  mins 

March    10th    

6  '31  a  m 

6  '06  p  m 

11  hrs  35  mins 

March    21st  §    

6:09  a.  m. 

6  '22  p  m. 

12  hrs  13  mins. 

March  31st    

5:49  a.  m. 

6:36  p  m 

12  hrs.  47  mins. 

April  1st    . 

5-47  a  m 

6*37  p  m 

12  hrs  50  mins 

April    10th     

5:29  a.  m. 

6'49  p  m 

13  hrs  20  mins 

April    20th 

5  '11  a  m 

7'03   p   m 

13  hrs  52  mins 

April    30th    

4:54  a.  m. 

7:16   p.  m. 

14  hrs.  22  mins. 

"Central  Standard  time. 
tWinter  Solstice,  shortest  day. 
^Perihelion,  Earth  nearest  to  Sun. 
§Vernal  Equinox. 


OF  THE 

UNIVERSITY 


1914 

Press  of  Christie  Lithograph  &  Printing  Co., 
Duluth,  Minn. 


• 


14  DAY  USE 

RETURN  TO  DESK  FROM  WHICH  BORROWED 

LOAN  DEPT. 

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Renewed  books  are  subject  to  immediate  recall. 


f    tftfTtV 

'Shfl13 

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fxt-Q  D  L.D 

JAN  1  5  1963 

LD  21A-50m-12,'-60 
(B6221slO)4761 


University  of  California 
Berkeley 


28904 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


